Association of Bonding-Wire Displacement With Gas Bubbles in Plastic-Encapsulated Integrated Circuits

Evidence for the unexpected association of displaced wires with gas bubbles in plastic-encapsulated integrated circuits is presented. It is also shown that bubbles can be caused by entrainment of air in the compound as it flows through the molding tool. A mechanism which accounts for the frequent association of displaced bonding wires with the gas bubbles is suggested.